The present invention relates to a safety device for gas turbine engines and more particularly to an improved method of and apparatus for anticipatory detection and prevention of compressor stall caused by air inlet distortion.
Axial and centrifugal compressors in gas turbine engines for aircraft are susceptible to a stall condition which occurs when the pressure ratio across one or more stages of the compressor becomes too great. Stall is manifested by either a serious reduction or a reversal of air flow through the compressor and consequent reduction or complete loss of power. Occasionally, a rigorous aircraft maneuver such as a rapidly accelerating climbing turn causes severe air distortion at the engine inlet resulting in the onset of a compressor stall condition. An important factor to be considered in avoiding an impending stall is the lead time necessary to detect and commence corrective measures. Since prior art devices typically detect the onset of stall by sensing in-situ pressure conditions at or rearwardly of the compressor stages, valuable time may be lost in restoring the gas turbine engine to a stable operating condition.